/*
 *	TFormatConversionProvider.java
 *
 *	This file is part of Tritonus: http://www.tritonus.org/
 */

/*
 *  Copyright (c) 1999, 2000 by Matthias Pfisterer
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library General Public License as published
 *   by the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
|<---            this code is formatted to fit into 80 columns             --->|
*/

package org.tritonus.share.sampled.convert;

import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.spi.FormatConversionProvider;

import org.tritonus.share.TDebug;
import org.tritonus.share.sampled.AudioFormats;

/**
 * Base class for all conversion providers of Tritonus.
 *
 * @author Matthias Pfisterer
 */
public abstract class TFormatConversionProvider extends FormatConversionProvider {
	protected static final AudioFormat.Encoding[] EMPTY_ENCODING_ARRAY = new AudioFormat.Encoding[0];
	protected static final AudioFormat[] EMPTY_FORMAT_ARRAY = new AudioFormat[0];

	// $$fb2000-10-04: use AudioSystem.NOT_SPECIFIED for all fields.
	@Override
	public AudioInputStream getAudioInputStream(AudioFormat.Encoding targetEncoding, AudioInputStream audioInputStream) {
		AudioFormat sourceFormat = audioInputStream.getFormat();
		AudioFormat targetFormat = new AudioFormat(targetEncoding, AudioSystem.NOT_SPECIFIED, // sample rate
				AudioSystem.NOT_SPECIFIED, // sample size in bits
				AudioSystem.NOT_SPECIFIED, // channels
				AudioSystem.NOT_SPECIFIED, // frame size
				AudioSystem.NOT_SPECIFIED, // frame rate
				sourceFormat.isBigEndian()); // big endian
		if (TDebug.TraceAudioConverter) {
			TDebug.out("TFormatConversionProvider.getAudioInputStream(AudioFormat.Encoding, AudioInputStream):");
			TDebug.out("trying to convert to " + targetFormat);
		}
		return getAudioInputStream(targetFormat, audioInputStream);
	}

	/**
	 * WARNING: this method uses <code>getTargetFormats(AudioFormat.Encoding, AudioFormat)</code> which may create infinite loops if the latter is overwritten.
	 * <p>
	 * This method is overwritten here to make use of org.tritonus.share.sampled.AudioFormats.matches and is considered temporary until AudioFormat.matches is corrected in the JavaSound API.
	 */
	/*
	 * $$mp: if we decide to use getMatchingFormat(), this method should be implemented by simply calling getMatchingFormat() and comparing the result against null.
	 */
	@Override
	public boolean isConversionSupported(AudioFormat targetFormat, AudioFormat sourceFormat) {
		if (TDebug.TraceAudioConverter) {
			TDebug.out(">TFormatConversionProvider.isConversionSupported(AudioFormat, AudioFormat):");
			TDebug.out("class: " + getClass().getName());
			TDebug.out("checking if conversion possible");
			TDebug.out("from: " + sourceFormat);
			TDebug.out("to: " + targetFormat);
		}
		AudioFormat[] aTargetFormats = getTargetFormats(targetFormat.getEncoding(), sourceFormat);
		for (int i = 0; i < aTargetFormats.length; i++) {
			if (TDebug.TraceAudioConverter) {
				TDebug.out("checking against possible target format: " + aTargetFormats[i]);
			}
			if (aTargetFormats[i] != null && AudioFormats.matches(aTargetFormats[i], targetFormat)) {
				if (TDebug.TraceAudioConverter) {
					TDebug.out("<result=true");
				}
				return true;
			}
		}
		if (TDebug.TraceAudioConverter) {
			TDebug.out("<result=false");
		}
		return false;
	}

	/**
	 * WARNING: this method uses <code>getTargetFormats(AudioFormat.Encoding, AudioFormat)</code> which may create infinite loops if the latter is overwritten.
	 * <p>
	 * This method is overwritten here to make use of org.tritonus.share.sampled.AudioFormats.matches and is considered temporary until AudioFormat.matches is corrected in the JavaSound API.
	 */
	public AudioFormat getMatchingFormat(AudioFormat targetFormat, AudioFormat sourceFormat) {
		if (TDebug.TraceAudioConverter) {
			TDebug.out(">TFormatConversionProvider.isConversionSupported(AudioFormat, AudioFormat):");
			TDebug.out("class: " + getClass().getName());
			TDebug.out("checking if conversion possible");
			TDebug.out("from: " + sourceFormat);
			TDebug.out("to: " + targetFormat);
		}
		AudioFormat[] aTargetFormats = getTargetFormats(targetFormat.getEncoding(), sourceFormat);
		for (int i = 0; i < aTargetFormats.length; i++) {
			if (TDebug.TraceAudioConverter) {
				TDebug.out("checking against possible target format: " + aTargetFormats[i]);
			}
			if (aTargetFormats[i] != null && AudioFormats.matches(aTargetFormats[i], targetFormat)) {
				if (TDebug.TraceAudioConverter) {
					TDebug.out("<result=true");
				}
				return aTargetFormats[i];
			}
		}
		if (TDebug.TraceAudioConverter) {
			TDebug.out("<result=false");
		}
		return null;
	}

}

/*** TFormatConversionProvider.java ***/
